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Tuberculin Test Procedure and Results

Know about the tuberculin test procedure, why it is done, the test procedure, how to perform the test and the interpretation of the test result.

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Written by Dr. Siri Nallapu

Reviewed by Dr. M L Ezhilarasan MBBS

Last updated on 28th Aug, 2025

Tuberculin Test

Introduction

Tuberculosis (TB) is a serious but treatable infection caused by the bacterium Mycobacterium tuberculosis. Early detection is crucial to prevent its spread and complications. One of the key tests used to check for TB exposure is the Tuberculin Skin Test (TST), also known as the Mantoux test.

If you or a loved one has been advised to take this test, you may have questions about how it works, what to expect, and what the results mean. This article will guide you through the entire process in simple terms.

What Is a Tuberculin Test?

The Tuberculin Test is a skin test that helps determine if a person has been exposed to TB bacteria. It does not confirm an active TB infection but indicates whether the immune system has reacted to the bacteria at some point.

Consult a Pulmonologist for Personalised Advice

Dr. Varun Rajpal, Pulmonology Respiratory Medicine Specialist

Dr. Varun Rajpal

Pulmonology Respiratory Medicine Specialist

12 Years • MBBS, DNB Respiratory Medicine, EDARM, IDCCM,FCCS,FSM, Certificate course in Diabetes.

Noida

DR. VARUN RAJPAL Lungs And Respiratory Care clinic., Noida

1250

800

No Booking Fees

Dr. Hyder, Pulmonology Respiratory Medicine Specialist

Dr. Hyder

Pulmonology Respiratory Medicine Specialist

5 Years • MBBS, MD (PULMONOLOGY)

Guntur

Kalam chest and multi-speciality clinic, Guntur

500

500

No Booking Fees

Why Is It Done?

  • To screen people at high risk of TB (e.g., healthcare workers, close contacts of TB patients).
  • To check for latent TB (an inactive form that could become active later).
  • Before starting certain treatments (like immunosuppressive drugs), which could reactivate TB.

How Is the Test Performed?

The procedure is simple and quick, performed in a clinic or doctor’s office. Here’s what happens:

Step 1: Cleaning the Skin

  • A healthcare provider will clean a small area on your forearm with alcohol.

Step 2: Injection

  • A tiny amount of purified protein derivative (PPD)—a harmless TB protein—is injected just under the skin using a small needle.
  • You may feel a slight pinch, but it’s not painful.

Step 3: Waiting Period

  • You must return 48–72 hours later (2–3 days) to have the injection site checked for a reaction.
  • Do not scratch or cover the area with bandages, as this can affect results.

Understanding Your Results

After 2–3 days, a doctor or nurse will measure the swelling (induration, redness) at the injection site.

What Do the Results Mean?

False Positives/Negatives:

  • False Positive: Previous BCG vaccine (given in some countries) or exposure to similar bacteria.
  • False Negative: Weak immune system (HIV, malnutrition, recent infections).

If your test is positive, your doctor may recommend further tests (chest X-ray, sputum test) to check for active TB.

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Reaction Size 

 Interpretation

Less than 5mm

Likely negative (no TB exposure) 

5–10mm

Positive in high-risk groups (e.g., HIV patients, recent TB contacts)

More than 10mm

Positive in most people

What If the Test Is Positive?

A positive result means you have been exposed to TB bacteria, but it doesn’t always mean you have an active infection.
Next Steps:

  1.  Chest X-ray: To check for lung abnormalities.
  2.  Sputum Test: If active TB is suspected, a mucus sample is tested.
  3.  Treatment for Latent TB: If no active infection is found, you may be given preventive medication to stop TB from becoming active later.

Tips for Managing TB Exposure

If you have latent or active TB, follow these steps to stay healthy:

  • Take Medications as Prescribed – Skipping doses can lead to drug-resistant TB. Maintain Good Hygiene – Cover your mouth when coughing/sneezing.
  • Eat a Balanced Diet – Strengthen your immune system with fruits, vegetables, and proteins.
  • Avoid Smoking & Alcohol – These weaken your lungs and immunity.
  • Regular Follow-ups – Ensure the infection is under control.

When to Consult a Doctor?

Seek medical advice if:

  • You’ve been in close contact with a TB patient.
  • You have symptoms like prolonged cough, fever, night sweats, or weight loss.
  • Your tuberculin test shows a positive reaction.

Early detection and treatment can prevent serious complications.

Final Thoughts

The Tuberculin Test is a simple and effective way to check for TB exposure. While a positive result can be concerning, remember that TB is treatable. If you’re at risk or have symptoms, getting tested is the best way to protect yourself and others.

Consult a Pulmonologist for Personalised Advice

Dr. Varun Rajpal, Pulmonology Respiratory Medicine Specialist

Dr. Varun Rajpal

Pulmonology Respiratory Medicine Specialist

12 Years • MBBS, DNB Respiratory Medicine, EDARM, IDCCM,FCCS,FSM, Certificate course in Diabetes.

Noida

DR. VARUN RAJPAL Lungs And Respiratory Care clinic., Noida

1250

800

No Booking Fees

Dr. Hyder, Pulmonology Respiratory Medicine Specialist

Dr. Hyder

Pulmonology Respiratory Medicine Specialist

5 Years • MBBS, MD (PULMONOLOGY)

Guntur

Kalam chest and multi-speciality clinic, Guntur

500

500

No Booking Fees

Consult a Pulmonologist for Personalised Advice

Dr. Varun Rajpal, Pulmonology Respiratory Medicine Specialist

Dr. Varun Rajpal

Pulmonology Respiratory Medicine Specialist

12 Years • MBBS, DNB Respiratory Medicine, EDARM, IDCCM,FCCS,FSM, Certificate course in Diabetes.

Noida

DR. VARUN RAJPAL Lungs And Respiratory Care clinic., Noida

1250

800

No Booking Fees

Dr Chetan Kumar, Pulmonology Respiratory Medicine Specialist

Dr Chetan Kumar

Pulmonology Respiratory Medicine Specialist

27 Years • MBBS, MD TB & CHEST DISEASE

Delhi

Cronus Hospital, Delhi

799

No Booking Fees

Dr. Ashish Kumar, Pulmonology Respiratory Medicine Specialist

Dr. Ashish Kumar

Pulmonology Respiratory Medicine Specialist

14 Years • Doctor of Medicine, D.T.C.D

Noida

Noida Asthma and chest clinic, Noida

625

500

No Booking Fees

Dr. Hyder, Pulmonology Respiratory Medicine Specialist

Dr. Hyder

Pulmonology Respiratory Medicine Specialist

5 Years • MBBS, MD (PULMONOLOGY)

Guntur

Kalam chest and multi-speciality clinic, Guntur

500

500

No Booking Fees

Dr. Lokesh Kumar Garg, Pulmonology Respiratory Medicine Specialist

Dr. Lokesh Kumar Garg

Pulmonology Respiratory Medicine Specialist

15 Years • MBBS,DTCD,PGDS

Faridabad

Arsh Hospital, Faridabad

625

500

Consult a Pulmonologist for Personalised Advice

Dr. Varun Rajpal, Pulmonology Respiratory Medicine Specialist

Dr. Varun Rajpal

Pulmonology Respiratory Medicine Specialist

12 Years • MBBS, DNB Respiratory Medicine, EDARM, IDCCM,FCCS,FSM, Certificate course in Diabetes.

Noida

DR. VARUN RAJPAL Lungs And Respiratory Care clinic., Noida

1250

800

No Booking Fees

Dr Chetan Kumar, Pulmonology Respiratory Medicine Specialist

Dr Chetan Kumar

Pulmonology Respiratory Medicine Specialist

27 Years • MBBS, MD TB & CHEST DISEASE

Delhi

Cronus Hospital, Delhi

799

No Booking Fees

Dr. Ashish Kumar, Pulmonology Respiratory Medicine Specialist

Dr. Ashish Kumar

Pulmonology Respiratory Medicine Specialist

14 Years • Doctor of Medicine, D.T.C.D

Noida

Noida Asthma and chest clinic, Noida

625

500

No Booking Fees

Dr. Hyder, Pulmonology Respiratory Medicine Specialist

Dr. Hyder

Pulmonology Respiratory Medicine Specialist

5 Years • MBBS, MD (PULMONOLOGY)

Guntur

Kalam chest and multi-speciality clinic, Guntur

500

500

No Booking Fees

Dr. Lokesh Kumar Garg, Pulmonology Respiratory Medicine Specialist

Dr. Lokesh Kumar Garg

Pulmonology Respiratory Medicine Specialist

15 Years • MBBS,DTCD,PGDS

Faridabad

Arsh Hospital, Faridabad

625

500

Get Your Health Assessed

2800(₹7000)60% off

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